Effects of pre-strain on uniaxial ratcheting and fatigue failure of Z2CN18.10 austenitic stainless steel

Effects of both tensile and compressive pre-strain on cyclic deformation of Z2CN18.10 austenitic stainless steel under stress cycling with mean stress are studied. As compared to as-received material, ratcheting strain of subsequent stress cycling decreases with increasing tensile pre-strain (TP) level. Lower level of compressive pre-strain (CP) is found to accelerate ratcheting strain accumulation while higher level of CP retards the accumulation. Tensile pre-straining is beneficial to ratcheting–fatigue life while compressive pre-straining is detrimental. A modified fatigue model to address the effect of pre-straining is proposed to predict the fatigue lives of the stress cycling tests with mean stress.